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Liquid Biopsy
A liquid biopsy, also known as fluid biopsy or fluid phase biopsy, is the sampling and analysis of non-solid biological tissue, primarily blood. Like traditional biopsy, this type of technique is mainly used as a diagnostic and monitoring tool for diseases such as cancer, with the added benefit of being largely non-invasive. Liquid biopsies may also be used to validate the efficiency of a cancer treatment drug by taking multiple samples in the span of a few weeks. The technology may also prove beneficial for patients after treatment to monitor relapse. The clinical implementation of liquid biopsies is not yet widespread but is becoming standard of care in some areas. Types There are several types of liquid biopsy methods; method selection depends on the condition that is being studied. A wide variety of biomarkers may be studied to detect or monitor other diseases. For example, isolation of protoporphyrin IX from blood samples can be used as a diagnostic tool for atheroscleros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the circulatory system is also known as ''peripheral blood'', and the blood cells it carries, ''peripheral blood cells''. Blood is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume), and contains proteins, glucose, mineral ions, hormones, carbon dioxide (plasma being the main medium for excretory product transportation), and blood cells themselves. Albumin is the main protein in plasma, and it functions to regulate the colloidal osmotic pressure of blood. The blood cells are mainly red blood cells (also called RBCs or erythrocytes), white blood cells (also called WBCs or leukocytes) and platelets (also called thrombocytes). The most abundant cells in vertebrate blo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heart Attack
A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck or jaw. Often it occurs in the center or left side of the chest and lasts for more than a few minutes. The discomfort may occasionally feel like heartburn. Other symptoms may include shortness of breath, nausea, feeling faint, a cold sweat or feeling tired. About 30% of people have atypical symptoms. Women more often present without chest pain and instead have neck pain, arm pain or feel tired. Among those over 75 years old, about 5% have had an MI with little or no history of symptoms. An MI may cause heart failure, an irregular heartbeat, cardiogenic shock or cardiac arrest. Most MIs occur due to coronary artery disease. Risk factors include high blood pressure, smoking, diabetes, lack of e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Test
A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a hypodermic needle, or via fingerprick. Multiple tests for specific blood components, such as a glucose test or a cholesterol test, are often grouped together into one test panel called a blood panel or blood work. Blood tests are often used in health care to determine physiological and biochemical states, such as disease, mineral content, pharmaceutical drug effectiveness, and organ function. Typical clinical blood panels include a basic metabolic panel or a complete blood count. Blood tests are also used in drug tests to detect drug abuse. Extraction A venipuncture is useful as it is a minimally invasive way to obtain cells and extracellular fluid ( plasma) from the body for analysis. Blood flows throughout the body, acting as a medium that provides oxygen and nutrients to tissues and carries waste products back to the excretory systems for disposal. Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Typing
Blood compatibility testing is conducted in a medical laboratory to identify potential incompatibilities between blood group systems in blood transfusion. It is also used to diagnose and prevent some complications of pregnancy that can occur when the baby has a different blood group from the mother. Blood compatibility testing includes blood typing, which detects the antigens on red blood cells that determine a person's blood type; testing for unexpected antibodies against blood group antigens (antibody screening and identification); and, in the case of blood transfusions, mixing the recipient's plasma with the donor's red blood cells to detect incompatibilities ( crossmatching). Routine blood typing involves determining the ABO and RhD (Rh factor) type, and involves both identification of ABO antigens on red blood cells (forward grouping) and identification of ABO antibodies in the plasma (reverse grouping). Other blood group antigens may be tested for in specific clinical situ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Percutaneous Umbilical Cord Blood Sampling
Percutaneous umbilical cord blood sampling (PUBS), also called cordocentesis, fetal blood sampling, or umbilical vein sampling is a diagnostic genetic test that examines blood from the fetal umbilical cord to detect fetal abnormalities. Fetal and maternal blood supply are typically connected in utero with one vein and two arteries to the fetus. The umbilical vein is responsible for delivering oxygen rich blood to the fetus from the mother; the umbilical arteries are responsible for removing oxygen poor blood from the fetus. This allows for the fetus’ tissues to properly perfuse. PUBS provides a means of rapid chromosome analysis and is useful when information cannot be obtained through amniocentesis, chorionic villus sampling, or ultrasound (or if the results of these tests were inconclusive); this test carries a significant risk of complication and is typically reserved for pregnancies determined to be at high risk for genetic defect. It has been used with mothers with immune ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Umbilical Cord
In placental mammals, the umbilical cord (also called the navel string, birth cord or ''funiculus umbilicalis'') is a conduit between the developing embryo or fetus and the placenta. During prenatal development, the umbilical cord is physiologically and genetically part of the fetus and (in humans) normally contains two arteries (the umbilical arteries) and one vein (the umbilical vein), buried within Wharton's jelly. The umbilical vein supplies the fetus with oxygenated, nutrient-rich blood from the placenta. Conversely, the fetal heart pumps low-oxygen, nutrient-depleted blood through the umbilical arteries back to the placenta. Structure and development The umbilical cord develops from and contains remnants of the yolk sac and allantois. It forms by the fifth week of development, replacing the yolk sac as the source of nutrients for the embryo. The cord is not directly connected to the mother's circulatory system, but instead joins the placenta, which transfers materials t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescent In Situ Hybridization
Fluorescence ''in situ'' hybridization (FISH) is a molecular cytogenetic technique that uses fluorescent probes that bind to only particular parts of a nucleic acid sequence with a high degree of sequence complementarity. It was developed by biomedical researchers in the early 1980s to detect and localize the presence or absence of specific DNA sequences on chromosomes. Fluorescence microscopy can be used to find out where the fluorescent probe is bound to the chromosomes. FISH is often used for finding specific features in DNA for use in genetic counseling, medicine, and species identification. FISH can also be used to detect and localize specific RNA targets (mRNA, lncRNA and miRNA) in cells, circulating tumor cells, and tissue samples. In this context, it can help define the spatial-temporal patterns of gene expression within cells and tissues. Probes – RNA and DNA In biology, a probe is a single strand of DNA or RNA that is complementary to a nucleotide sequence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karyotyping
A karyotype is the general appearance of the complete set of metaphase chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by determining the chromosome complement of an individual, including the number of chromosomes and any abnormalities. A karyogram or idiogram is a graphical depiction of a karyotype, wherein chromosomes are organized in pairs, ordered by size and position of centromere for chromosomes of the same size. Karyotyping generally combines light microscopy and photography, and results in a photomicrographic (or simply micrographic) karyogram. In contrast, a schematic karyogram is a designed graphic representation of a karyotype. In schematic karyograms, just one of the sister chromatids of each chromosome is generally shown for brevity, and in reality they are generally so close together that they look as one on photomicrographs as well u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell-free Fetal DNA
Cell-free fetal DNA (cffDNA) is fetal DNA that circulates freely in the maternal blood. Maternal blood is sampled by venipuncture. Analysis of cffDNA is a method of non-invasive prenatal diagnosis frequently ordered for pregnant women of advanced maternal age. Two hours after delivery, cffDNA is no longer detectable in maternal blood. Background cffDNA originates from placental trophoblasts. Fetal DNA is fragmented when placental microparticles are shed into the maternal blood circulation. cffDNA fragments are approximately 200 base pairs (bp) in length. They are significantly smaller than maternal DNA fragments. The difference in size allows cffDNA to be distinguished from maternal DNA fragments. Approximately 11 to 13.4 percent of the cell-free DNA in maternal blood is of fetal origin. The amount varies widely from one pregnant woman to another. cffDNA is present after five to seven weeks gestation. The amount of cffDNA increases as the pregnancy progresses. The quantity of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prenatal Diagnosis
Prenatal testing consists of prenatal screening and prenatal diagnosis, which are aspects of prenatal care that focus on detecting problems with the pregnancy as early as possible. These may be anatomic and physiologic problems with the health of the zygote, embryo, or fetus, either before gestation even starts (as in preimplantation genetic diagnosis) or as early in gestation as practicable. Screening can detect problems such as neural tube defects, chromosome abnormalities, and gene mutations that would lead to genetic disorders and birth defects, such as spina bifida, cleft palate, Down syndrome, Tay–Sachs disease, sickle cell anemia, thalassemia, cystic fibrosis, muscular dystrophy, and fragile X syndrome. Some tests are designed to discover problems which primarily affect the health of the mother, such as PAPP-A to detect pre-eclampsia or glucose tolerance tests to diagnose gestational diabetes. Screening can also detect anatomical defects such as hydrocephalus, anencephal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiplex (assay)
In the biological sciences, a multiplex assay is a type of immunoassay that uses magnetic beads to simultaneously measure multiple analytes in a single experiment. A multiplex assay is a derivative of an ELISA using beads for binding the capture antibody. Multiplex assays are still more common in research than in clinical settings. In a multiplex assay, microspheres of designated colors are coated with antibodies of defined binding specificities. The results can be read by flow cytometry Flow cytometry (FC) is a technique used to detect and measure physical and chemical characteristics of a population of cells or particles. In this process, a sample containing cells or particles is suspended in a fluid and injected into the flo ... because the beads are distinguishable by fluorescent signature. The number of analytes measured is determined by the number of different bead colors. Multiplex assays within a given application area or class of technology can be further stratified ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ELISA
The enzyme-linked immunosorbent assay (ELISA) (, ) is a commonly used analytical biochemistry assay, first described by Eva Engvall and Peter Perlmann in 1971. The assay uses a solid-phase type of enzyme immunoassay (EIA) to detect the presence of a ligand (commonly a protein) in a liquid sample using antibodies directed against the protein to be measured. ELISA has been used as a diagnostic tool in medicine, plant pathology, and biotechnology, as well as a quality control check in various industries. In the most simple form of an ELISA, antigens from the sample to be tested are attached to a surface. Then, a matching antibody is applied over the surface so it can bind the antigen. This antibody is linked to an enzyme and then any unbound antibodies are removed. In the final step, a substance containing the enzyme's substrate is added. If there was binding, the subsequent reaction produces a detectable signal, most commonly a color change. Performing an ELISA involves at least ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
